Internet infrastructure is the backbone of the digital world, comprising a vast network of physical and virtual components that enable seamless communications and data exchange globally. It includes key elements for data routing and exchange, Internet access, communication protocols, and more. Data transmission is facilitated through wired, microwave, and fiber-optic links, along with routing equipment. Critical software services, such as website hosting, the Domain Name System (DNS), email, database servers, authentication and authorization systems, and storage solutions, are also integral to the internet infrastructure. The topics included in this book on internet infrastructure are of utmost significance and bound to provide incredible insights to readers. This book presents the complex subject in the most comprehensible and easy to understand language. This book will serve as a reference to a broad spectrum of readers.